Method of forming ball centers



Patented Feb. 20, 1934 UNITED STATES PATENT OFFICE METHOD OF FORMING BALL CENTERS pany N 0 Drawing.

Application December 9, 1932,

Serial No. 646,479, and in Great Britain December 12, 1931 Claims.

This invention has reference to golf and the like balls and in particular the type in which the interior of the ball either in part or in Whole is filled with liquid of a high state of mobility.

The object of this invention is to provide a new process for forming the liquids inside the ball so that the initial operations of the manufacture of the ball may have the advantages accruing from the use of a solid centre, while in the finished ball the advantages of a liquid core may be gained.

In the main, the liquid is contained either in the member which forms the cover of the ball or in a hollow spherical member constituting a component of the ball around which other components may be built, for example, a shell of tensely Wound elastic thread and finally a cover of gutta-percha or the like.

According to this invention, the method for producing liquid centres for or inside golf and the like balls comprises employing two, or more, substances which undergo mutual liquefaction when brought into contact with one another.

The substances in their initial state of use are preferably solid or substantially non-mobile, and they are selected so that the physical change in their structure can be occasioned without additional heat, namely, in normal atmospheric temperatures.

Further, preferably the substances are chosen so as to produce an eutectic mixture having an eutectic or fusing point at a temperature preferably not greater than normal atmospheric temperature and in any case within the temperature of storage or use.

Preferably, the substances are introduced independently of one another and are brought into contact as a result of operations essential to the formation of their casings.

Furthermore, the invention may embrace means whereby the substances upon conversion are prevented from migrating or percolating into other bounds.

In practicing this invention, we prefer to mould the substances in a plurality of partspherical members which combine to form a hollow sphere, which, itself may constitute the cover of the ball, or the casing of a component around which other components are built.

In one manner of performing the invention, we use as one of the substances an aqueous gel or jelly, e. g., silicic acid, agar agar, starch, starch acetate, gum tragacanth, algin, Iceland moss, gelatin, pectin, or other similar material, and for the other We employ a substance having a marked solubility in water, and preferably such as also contains acid radicals occupying a prominent position in the lyotropic series favouring the conversion from gel to sol, for instance, sodium thiosulphate, sodium acetate, ammonium chloride, ammonium thiocyanate or potassium thiocyanate. Where such salts form hydrated molecules with water of crystallization we prefer to use them in this condition.

As an example, the aqueous jelly is first given the desired shape by casting in a fluid or molten state and allowed to set. The mould, indeed, may be the part-spherical shell employed as one half of the permanent encasement for the material to be liquefied in the ball. Into the other hemispherical shell, we place or form a solid mass of the salt which may have been premoulded or may have been shaped therein, e. g., pouring a molten hydrated crystalline or other suitable salt, e. g., sodium acetate or sodium thiosulphate which preferably has been melted without substantial loss of water of crystallization.

Then by uniting the two hemispherical members the substances are brought into intimate contact and in consequence, presumably of the osmotic pressure exercised by the saline substance results in a withdrawal of the water from the gel or jelly, so that the substances become mutually liquid.

The aqueous gel, as previously inferred, is in a colloidal state and it will be apparent that its consistency may be controlled e. g., by modifying its liquid content.

Also the density of the solution of the saline or crystalline solid may be controlled in any suitable manner, as may the liquid in general.

In accordance with another form of our invention, We take two substances of which at least one has a melting point above ordinary atmospheric temperature and which, however, when mixed produce a eutectic of melting point below normal atmospheric temperature. As an example of two such materials, there may be cited camphor and salol or camphor and a dihydroxy benzene such as catechol.

As previously stated a resultant of the intimate contact of the substances is a conversion to fluidity and by varying the constituents and if desired with the addition of other suitable substances the mobility of the fluid can be altered.

In further explanation, though additional heat is not an essential for the operation of this invention we can choose the substances if we so desire so that the physical change referred to will be accelerated at a temperature greater than atmospheric, and particularly so that liquefaction will be expedited during any heat moulding operation to which any component, or the ball as a Whole, may be subjected.

In a furtherfeature, and so as to prevent the liquid from penetrating into or through the encasement for the liquid by diffusion, we may make the components of the casing of suitable impervious substance, or smear the internal surface of the casing components with a suitable impervious substance, for example, a flexible composition of nitroor acetyl-cellulose, and may wrap the joints between the components with any suitable material so as to facilitate a liquid proof joint.

In a further feature and so as to delay the initial mutual liquefaction of the constituents, we may interpose between them, during the assembling of the centre or earlier a complete or partial film of a material which will act as a temporary barrier, for example, of relatively dry gelatin.

The following are examples of carrying the invention into, effect-- Example 1 Two hemispherical shells are moulded and semi-vulcanized from a vulcanizable mix substantially, of the following composition:--

Parts by weight Rubber 100 Sulphur 8 Zinc oxide 8 Mercaptobenz-thiazole 1.2 Lead dust 264 the two hemispherical members by applying a at any time by Example 2 A hollow fluid-filled centre is made in a similarmanner using ammonium nitrate and 10% gelatin ,jelly in the 2, half-shells. The resulting fluid mixture has a specific gravity of 1.31..

Example 3 As another example the solid initially present consists of zinc nitrate 26 parts and ammonium I nitrate 21 parts. They fluid mixture obtained eventually in the hollowcentre has a specific 'gravityof 1.41.

Having now particularly described and ascertained the .natureof our said invention and in what manner the same is to be performed, we declare that what we claim is 1. A method of forming ball centers liquid at normal temperatures which comprises separately forming parts of said center in solid form of substances solid at ordinary atmospheric temperatures that undergo liquefaction at ordinary atmospheric temperatures upon remaining in contact with each other and contacting and assembling said parts to a center and enclosing said assembled parts for liquefaction in an en closure impermeable to said substances.

. 2. A method of forming ball centers liquid at normal temperatures which comprises separately forming parts of said center in solid form of substances that undergo liquefaction upon remaining in contact with each other and contacting and assembling said parts to a center, while enclosing them in an enclosure that is impermeable to the liquid resultant from an admixture of said solids.

3. A method of forming ball centers liquid at normal temperatures which comprises separately forming parts of said center in solid form of sub stances that undergo liquefaction upon remaining in contact with each other at normal temperatures and contacting and assembling said parts to a center.

LA method as claimed in claim 1, wherein the substances chosen are such as to produce an eutectic mixture having a eutectic or fusing point at a temperature preferably not greater than normal atmospheric temperature and in any case within the temperature of storage or use.

5. A method as claimed in claim 1, wherein the substances are moulded in a plurality of part-spherical members which combine to form a hollow sphere.

6. A method'as claimed in claim 1, wherein as 3 one of. the substances an aqueous gel is employed and for the other is employed a substance havinga marked solubility in water.

'7. A method as claimed in claim 1, wherein an aqueous gel is employed as one of the substances and another contains acid. radicals occupying a prominent position in the lyotropic series.

8. Amethodas claimed in claim 1, wherein two substances are employed, wherein one at least has a melting point above ordinary atmospheric temperature which upon admixture with the other substance produces a eutectic of melting point below normal atmospheric temperature.

9. A method as claimed in claim 1, wherein the initial mutual liquifaction of the constituents is delayed at the assembling of the centre by interposing a film of a material which will actas a temporary barrier. I

10. A method of forming ball centers liquid at normal temperatures which comprises filling separate part spherical shells with solid substances that undergo liquefaction when brought into contact, then assembling said parts to form a complete sphere with said solid materials in contact at surface areas and sealing said shells to a completed sphere.

DOUGLAS FRANK TWISS. ALBERT EDWARD TONEY NEALE.

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